– Adenocarcinomas account for most prostate cancers. The rest are transitional cell, squamous cell, endometrioid, or sarcomatous cancers. (Also see Cancer.)
Causes and Incidence
The cause is unknown but appears to be related to endogenous hormones. Prostate cancer is the most commonly diagnosed cancer in men in the United States, with more than 165,000 cases reported annually. It is the third leading cause of cancer deaths in men and strikes those over age 50 most frequently (more than 85% are over age 65). The incidence and mortality rate are higher in black men.
Adenocarcinomas usually begin in the lower posterior prostate and grow slowly to encompass the entire gland. The tumor spreads directly to the bladder and levator ani muscles and, via the lymphatic system, throughout the pelvis. Metastasis occurs through the bloodstream to the bones, liver, lungs, and kidneys.
Early signs mimic benign prostatic hypertrophy; they include difficulty initiating and stopping the urinary stream, frequency and pain on urination, and a weak urinary stream.
The prognosis is good with tumors that have not metastasized (more than 70%), and even with metastasized disease, treatment may achieve long-term palliation. Complications of advanced disease include thrombosis, pulmonary emboli, retrograde ejaculation, and impotence.
Palpable nodules on digital rectal examination and an elevated prostate-specific antigen offer suspicions of tumor. A needle biopsy is the definitive follow-up.
Prostatectomy for localized tumor; transurethral resection when the bladder is involved; bilateral orchiectomy for metastatic disease.
Hormone therapy for palliation.
Radiation as a primary treatment alternative to surgery and for palliation; counseling for changes in sexual functioning.